First, FUS mutations, although rare in non-ALS cases, have been found in cases with frontotemporal dementia, either isolated13,14 or as an initial presentation of ALS-FTD15,16, as well as in patients with initial chorea17, mental retardation18, psychosis or dementia19, and essential tremor20. The gene discussed is FUS; the disease is amyotrophic lateral sclerosis.